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Driving without the radio installed

Discussion in 'Gen 2 Prius Audio and Electronics' started by oly_57mpg, Nov 20, 2008.

  1. oly_57mpg

    oly_57mpg New Member

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    Driving with out the radio installed. In short, don't do it.

    The radio seems to be an integral part of the overall MFD functionality. Without the radio plugged in, most of the buttons on the MFD do not work. The AC controls on the MFD do not function.
    The Map/GPS on the MFD do not function.
    The trip info will stay on the instantaneous info but will NOT show the battery condition or the power flow.

    The Air conditioner controls on the steering wheel work but the rest of the control buttons on the steering wheel do not.

    Looking at the block diagram and the schematics for the radio, it looks like CN703 and CN701 are a pass-through for the AVC-LAN and with out a cable connecting the two the functionality of the MFD is limited.

    If anyone decides to remove their radio, remember to run at least two lines from CN703 to CN701.
    CN703,P09 = CN701,P15
    CN703,P10 = CN701,P05
     
  2. oly_57mpg

    oly_57mpg New Member

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    Well, I take that back.

    Even though the head unit/stereo does indeed pass AVC-LAN (IEBus) between the two connectors it does not seem to effect the failures of the MFD buttons... If CN703 (five wires: SW1, SW2, TX -/+, and ground) is the only cable connected to the stereo the buttons and MFD work fine.
     
  3. rigormortis

    rigormortis Active Member

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    in a non nav system, the am/fm radio is the master device in the av-lan chain, with all the other devices being slaves
     
  4. oly_57mpg

    oly_57mpg New Member

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    In retrospect, this was an incredibly dumb post on my part. The issue with the AC and Navigation not working was solely due to the AVC-LAN not being terminated by a resistor.

    When I added a 60 Ohm resistor to pins 9 and 10 on CN703 on the radio harness all of the features but the audio system worked again.
     
  5. Thane

    Thane Junior Member

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    Does this mean I can permanently remove the radio and have all the MFD functions work normally if I simply install a 60ohm resistor between pins 9 and 10?
     
  6. dolj

    dolj Senior Member

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    It should be a 68 Ω resistor if that makes a difference.
     
    ColoradoCrow and Thane like this.
  7. Thane

    Thane Junior Member

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    Okay thanks for that. Very much. I'm going to give this a try with the 68 ohm resistor.The radio is already out and I have all the aforementioned problems. We'll see how it goes and I'll post the results here.